In lens systems for military, marine, industrial, outer space, or other rugged use, various machine vision systems having zoom and focus capability are used. However, one problem with these systems is that typical commercial zoom and focus lenses have mechanisms that are not sufficiently robust for these uses.
One possible solution is to use multiple cameras and lens systems instead of using one lens system. Some disadvantages to this approach are the increased cost, volume, and mass of having multiple cameras and lens systems.
Another possible solution is to use standard commercial lens systems that have mechanical devices to zoom the lens. One disadvantage to this approach is that a failing commercial lens system cannot be repaired or replaced in unmanned situations and these lens systems tend to mechanically fail due to shock, extreme changes in temperature, etc. Attempting to make these types of lens systems more robust makes these lens systems tend to be large and complicated (e.g. most lens systems require three or more independent lens group motions to operate).
There have been single motion zoom lens systems used previously, however, these systems have been used for infrared systems and the image quality has not been suitable for visible light applications.
Therefore, there is a need for a low risk, single unit, zoom and focus lens with sufficient quality for use in a visible spectrum camera. While the examples shown herein are discussed as for use in the visible spectrum, it is understood that they also apply to systems using portions of the UV and NIR spectrums as well.